Leather-stretching device.



No. 687,00l. Patented m I9, 1901.

. J. EALDWELL.

LEATHER STBETCHING DEVICE.

(Application filed Mar. 26, 1900. Renewed Dec. 1'7, 1900,)

(No Model.)

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I z's Z Z faraway UNITED STATES JOHN CALDWELL, OF MINNEAPOLIS,MINNESOTA, ASSIGNOR TO THE WV. S.

PATENT OFFICE.

NOTT COMPANY, OF MINNEAPOLIS, MINNESOTA, A CORPORATION.

LEATHER-STRETCHING DEVICE.

SPECIFICATION forming part of LettersPatent No. 687,001, dated November19, 1901.

Application filed March 26, 1900. Renewed December 171' 1900. Serial No.40,215. (No model.)

T0 on whom it may concern:

Be it known that I, J OHN CALDWELL, a citizen of the United States,residing at Minneapolis, in the county of Hennepin and State ofMinnesota, have invented certain new and useful Improvements inLeather-Stretching Devices, of which the following isa specification.

My invention relates to leather-stretching machines, and particularly tothe devices employed in such machines for holding the leather byengaging marginal portions of it, such devices having suitableconnections with the stretcher-heads or other proper part of themachine; and the objectof the present invention is to provide convenientmeans for pivotally connecting such holders to the appropriate parts ofthe machine.

Myimprovements are illustrated in the accompanying drawings, in whichFigure 1 is a vertical longitudinal section of a portion of astretching-machine, showing one form of the improved holders inoperative connection with the machine. Fig. 2 isa plan view showingseveral of the leatherholders in operative positions. Fig. 3 is anenlarged sectional View on the line as a: of Fig. 2. Fig. 4 is a view ofthe under side of the bottom plate shown in Fig. 3. Figs. 5 and 6 aredetail views of the form of locking device shown in the precedingfigures. Fig. 7 is a plan view of one of the holders and a portion ofthe perforated plate on which it rests and to which it may be locked.Fig. 8 is a sectional view on the line y y of Fig. 7. Fig. 9 shows asimilar plate with perforations of a different shape, and Fig. 10 showsaform of key or locking device used therewith.

In the drawings, 1 designates one of the side pieces of an ordinarystretcher-frame, which is so constructed as to support a side, back, orother division of leather during the operation of stretching it andafterward and until the leather is dried, set, and ready for use. Tothis frame is secured a fixed head or member 2 for supporting one end ofthe leather and the holders which are to connect it to the frame, and asliding head (not shown) is also to be provided for supporting the otherend of the leather and suitably arranged for connection with across-head or other moving part of a stretching-machine. My holdingdevices are adapted for use either with such fixed or movable head or inconnection with both heads.

The device for holding the leather consists of a plate or body 3, thefront portion of which is provided with suitable meansfor engaging theleather, the means .shown in the drawings being rows of tines or sharppins 4, adapted to be driven or forced through the leather. The rearportion or tailpiece of the body 3 is provided with a curved or othersuitable slot 5 or a corresponding series of separate holes, by means ofwhich it is adapted to be connected to the head 2 or other proper partof a stretcher apparatus. The purpose of such slot or holes is to enablethe connection to be made at such point as will bring the line of draft(indicated by the arrows a) approximately coincident with the medianline of the resistance offered by the engagement of the tines with themargin of leather whether the row of tines be at a right angle or at aninclination to such line of draft.

The means shown in Fig. 1 for connecting the holder to thestretcher-head is a pin, and the means shown in Figs. 2 to 6 is alockingpin or key 6, the pin or key passing loosely through the opening in thetailpiece. On the surface of the head 2 is a plate 7, which may havenumerous perforations 8 and having secured at its under side a series ofstrips 9, that are so placed as to coversmall portions of theperforations of the plate. The key 6 has a notch or annular groove 10near its lower end, and below the grooved portion the stem is cut awayat one side, as shown at 11, so that the lower end of the stem may bepassed through the plate 7 and below the strip 9 and then turned toposition to look, as indicated in Figs. 5 and 6. The advantage and theprincipal object in providing for the locking of the holder to the headby means of such key are to secure the holder in place at all times, andparticularly when it is desired to remove the leather from thestretcher. By having the holders locked down to the plate upon whichthey rest the leather after it has been stretched and dried may bepulled off, and thus more conveniently and readily freed from theholders than by pulling the latter from the leather,

as would be necessary if the holders were not locked to the head; butobviously the pins or keys need not have lugs or locking devices toenable them to connect the holders to the head for resisting the strainof tension during the stretching operation. It is to be understood thatin thus connecting the holders to the stretcher-head they are notprevented from horizontal swinging movement, for the pins or keys serveas pivots whereon the holders may turn laterally to adjust themselves tothe direction of the tension of the leather.

In the modified arrangement shown in Figs. 7 and 8 the perforations areof ordinary keyhole shape-that is, circular holes with narrowerelongations at one side, as shown at 12- to receive a key 13, havinglateral lugs 14 near its end, which by engaging the under surface of theplate 7 will lock the holder in place. In Figs. 9 and 10 theplate-perforations 15 are of oval or oblong shape adapted to receive akey 16, having lugs 17 at both sides, to be operated in the same way asthe key 13.

In putting such devices to use the leatherengaging means on theholder-bodies 3 are caused to engage the margin of the strip L ofleather, preferably on lines approximately parallel with the edges ofthe portions engaged, and the holders after being made to thus engagethe leather are connected to the stretcher-head by inserting the pins orkeys through the openings 5 into the appropriate holes in the plate 7.To prevent the leather from rising under the tension of stretching, atransverse bar 24 may be locked from side to side of the frame over thesurface of the leather. The sagging of the leather may be prevented byloose transverse bars 25 resting on the upper edges of the side pieces.The parts being thus arranged, power may be applied to the movable headand the leather stretched to the required degree, the movable head beinglocked by a dog engaging ratchetteeth in the usual manner, and when theoperation is completed the stretcher-frame, together with the leatherand its holders, may be removed from the machine and set'aside.

I do not herein claim the adjustable connection of a leather-holder to astretcher head by means which enable the holder to swing laterally onits connection, such sulr ject-matter of invention being reserved to beclaimed in an earlier application, Serial No. 1,424, filed January 15,1900, and the provision of means for varying the point of pivotalconnection of the holder to the coupling device conformably to thedirection of tension of the leather is reserved to be claimed in mypending application, Serial No. 10,128, filed March 26, 1900.

What I claim herein, and desire to secure by Letters Patent, is

1. A leather-holder, consisting of a body provided with leather-engagingmeans on its front portion and having in its rear portion a curved slotconcaved toward the leatherengaging means, for permitting the insertionand lateral adjustment of a pin, or key, in combination with astretcher'head on which the holder is supported and is laterally andlongitudinally adjustable, the stretcher-head having numerousperforations in its surface, and an independent pin, key, or likedevice, for entering the opening in the holder and a selectedperforation in the head to pivotally connect the holder to the head andpermit it to swing freely thereon under tension, substantially as setforth.

2. The combination with a stretcher-head having numerous perforations inits surface, of a series of independent leather-holders, consisting ofbodies provided with leatherengaging means on their forward portions andin their rear portions curved slots concaved toward the leather-engagingmeans, for permitting the insertion and lateral adjustment of pins orkeys, and supported and laterally and longitudinally adjustable uponsaid head, and independent pins, keys, or like devices, for entering theopenings in the holders and selected perforations in the stretcher-headto pivot-ally connect the holders to the head and permit them severallyto swing freely thereon under tension, substantially as set forth.

In testimony whereof I have hereunto set my hand this 20th day of March,1900.

JOHN OALD WELL.

In presence of-- P. H. GUNoKEL, M. F. HARRISON.

